Pressure gauge



sem 611927.

- H. J. BURKHARDT PRESSURE GAUGE Filed NovL 21. 1921 s Sheets-Sheet 1 Sept. 6, 1927; ,641,838

H. J. BURKHARDT PRESSURE GAUGE Filed Nov. 21. 1921 5 Sheets-She'et 3 if? z Patented Sept. 6, 1927. 2

UNITED STATES HENRY J-. BURKHAnn'r or MOUNT Erna-AIM; NE

LQNERGAN COMPANY, or PHILADELPHIA. PENNSYLVANIA, A CORPORATION or] PENNSYLVANIA.-

PATENT OFFICE.

JERSEY, ASSIGNOR To J. E.

PRESSURE GAUGE.

Application'filed November 21,1921. Serial No. 516,623.

One object of this invention is to provide av relatively simpleand accurate device for actuating and thereafter resetting the recording or telltale hand of a pressure gauge,thermometer or like instrument and the invention further contemplates novel means for operatively connecting the telltale hand with the pressure or temperature actuated member of the gauge so that said a! hand shall be moved thereby in but one direction.

A further object ofthe invention is to provide novel' means for preventing unauthorized operation of the device for resetting the telltale hand.

These objects and other advantageous ends I attain as hereinafter set forth, reference being had to the accompanying drawings, in which,

Fig. 1 is a front elevation of a gauge equipped with my invention;

Fig. 2 is'an elevation on, a larger'scale than Fig. 1, with the cover, dial and hands ren'iove-d-toshow the mechanism;

Fig.3 is a transverse section on the line 3+3, Fig. 2;

F ig. 4 is an enlarged vertical'sectlon on the'line 4'4,'Fig. 3, with portions of the hands in'position;

v Fig. 5 is a fragmentary section on the line 5'5,-Fig. 2; and

Fig. '6is an enlarged" fragmentary elevation showing the means for preventing unauthorized resetting of the telltalehand.

In the above drawings, 1 represents the body or main portion'of the flattened cylinpressure 'drical casing of a pressure gauge or other measuring or indicating instrument within which is mounted in the present case, a Bourdon tube 2 having a head 3 closing one end and at its opposite end connected to a conduit 4 extending out of the casing 1 and terminating in a threaded portion 5 for connection to any conduit or container of fluid under pressure. It is obviously immaterial whether the actuatingmember 2 be a Bourdon tube as shown or the movable or actuated element of a thermostat or other instrument, since my invention as hereafter described maybe advantageously employed Without essential change. Through a link 6 Fig. 3 the head 3 of the Bourdon tube or other pressure or temperature-responsive element is connected to one end of a bar 8 axial with the Fig. 4 longitudinally slotted to permit passage of a pivot' spindle 7 and rigidly connected- .by a screw 9 to a toothed segment 10 rotatably mounted, on said spindle. The

'teeth of this segment mesh with a pinion 11 fixed to'aspindle 12 supported within suitable bearings of a frame structure 13 Fig. 2 mounted within the casing 1 and having fixed'to its upper end a main or normal pressure indicating hand 14, as shown in Figs.3and 4. V V i The head 3 of the Bourdon tube or actuating element 2 has fixed in it a screw or pin 15 (Fig; 2) operative'in a slot 16 of a link 17 whose opposite end is pivoted to one end of a bar 18 fulcrumed on a pivot 19 copivot '7 and like it carried by the frame 13. This bar 17 is adjustably connected through the bar 18by a screw 20 with. a-second toothed segment 21 pivotally mounted on the spindle 19 and meshing with the teethv of a pinion 22 fixed to a' sleeve 23 mounted coaxially with the spindle 12. Said sleeve has fixed to itsupper end immediately under. the hand 14, a telltale or maximum hand 24, usually having a color'such as red, difierent from that oft-he normal indicating hand 14.

The above parts are so arranged that as the Bourdon tube 2 tends to straighten out under the action offiuid under pressure ad mitted to from the, conduit 4, it actuates both of the toothed segments 10 and 21 through the links .6 and 17 and through the: pinion 11 and spindle 12 on the one hand, and the pinion 22 and sleeve 23 on the, other, it actuates the two hands 14 and 24 to 7 equal amounts. When however the pres sure in the conduit 4and tube 2 is decreased, the resulting motion of said tube is transmitted through the link 6, toothed segment 10, pinion 11 and spindle 12 to the hand 14. Owing however to the slot 16 in the link 17, said movement is not transmitted to the telltale or maximum hand 24, which therefore remains stationary-at the furthest point to which it was moved by the action of the Bourdon' tube. It therefore indicates on the graduated face plate or dial 25 the maximum pressure of the fluid in the conduit 4'.

In. order to conveniently reset the telltale hand or needle 24, I' mount in the side of the casing 1 a guide sleeve 26 ig. 5) for the reception of. a plunger 27 having 'on its inner end within the casing a retaining collar 28 and on its outer end having a head 29. Ti'ithin the sleeve 26 under said head 1 provide a spring 30 whereby the plunger and head are normally retained in their outermost positions.

The plunger with its head and their associated parts are so proportioned that when it has heen forced inwardly as far as po. 'ble, it will engage the end oi the link 1i and so a ate said link with the segment 21 and sleeve that the telltale or maximum hand is returned to its zero position. Thus after any maximum reading oil the gauge has been noted. the maximum hand may he moved to zero or it the gauge is still under pressure, restored to a posi tion in which its reading is identical with that of the normal hand 1i.

As shown in Figs. 3 and 5, the outer edge of? the cylindrical casino 1 is threaded as indicated at 33 tor the reception of the bezel or cover and in order to prevent the recording hand being; reset by unauthorized persons, 1 pro ide the flange of said cover with an opening for the reception oi? a headed locking pin 34 having a reduced end formed to .iit into a transverse hole 535 in the plunger 27. When so engaged by the pin the plunger 27 cannot be pusaed in tmr enough to cause movement of the telltale hand and the withdrawal of the pin Set is prevented by a padlock 3'7 whose hasp passed through a transverse hole in said pin. The parts are so proportioned that the cover 2-36 cannot be unscrewed from the casing because the pin 34: cannot be withdrawn from the hole in the plunger 27 as long as the hasp of the padlock 37 is in place. Obviously therefore the telltale hand will remain in its position of maximum deflection until it is reset by the person having the key of the padlock 8'7, since this latter must be re- Willo moved before the locking pin can be withdrawn from the plunger.

1: claim:

1. The combination in a pressure gauge, at a dial having a series of pressure markings thereon, two coaxially pivoted and in dependently movable indicating hands both co-operating directly with the said dial, a

pressure :ponsive member, and two sepa rate t a ins o't mechanism connecting the said member with the two hands respectively to .iove them simultaneously and uniformly in one direction as the said member moves in one direction in accordance with increasing pre re, one ot the said trains including a lost motion connection which permits the corresponding hand to remain in a maxi mum pressure position when the said memher and the other hand move in the other dirertion in accordance with decreasing pressure.

The combination in a pressure gauge, oi a dial having;- a series of pressure mark inns thereon, two coaxially pivoted and independently movable indicating hands both (ac-operating directly with the said dial, a pressure responsive member, two separate trains oi mechanism connecting the said men'iher with the two hands respectively to move them simultaneously and uniformly in one direction as the said member moves in one direction in accordance with increasing pressure one of the said trains including; a lostinotion connection which permits the corresponding hand to remain in a maximum pressure position when the said member and the other hand move in the other direction in accordance with decreasing pressure, means for resetting the said maximum pressure hand, and a locking device adapted to prevent the operation of the resetting means.

HENRY J. BURKHARDT. 

